British Gas said on its website that its standard variable tariff for gas will rise by 10.4 percent and for electricity by 13.8 percent.

Ofgem had said that the cap on dual-fuel bills - both gas and electricity - would rise by 10.3 percent to £1,254 a year from April 1 for average energy use.

(Reporting by Sabina Zawadzki; Editing by David Goodman)